Change key lock



- July 21, 1959 E. N. KENNEDY 2,395,323

CHANGE KEY LOCK Filed March 51, 1955 l 4 Sheets-Sheet l I v r') l0 Y 4 EI J 30 I 17 C u 2/ I -30 f I? .22 2/ 25 r 20 X Z \NVE NTOR ERNEST N KENNEDY ATTORNEY Iuly21,1959 E. N. KENNEDY 2,895,323

Filed March 31, 1955 CHANGE KEY LOCK 4 Sheer,s--Sheet 2 29 I! I9 3/ 5 38 12 1 3o '23 i? 20 j y lo 22 2s 25 p E506, Z0 F5502 23 2o I a v 2 24 2/ 3o 23 n 'FMJ 38A 27 r} *m 28 o fi/ z fiom #250122,

\NVENTOR ERNEST N. KENNEDY ATTORNEY July 21, 1959 E. N. KENNEDY 2,395,323

CHANGE KEYJLOCK Filed March 31, 1955 r 4 Sheets-Sheet 3 ERNEST N. KENNEDY ATTORNEY.

July 21, 1959 E. N. KENNEDY 2,895,323

CHANGE KEYfLOCK Filed March 51, 1955 4 Sheets-Sheet 4 NVENTOR V Emqasw Nonsek'r K fiwrlw' RTTQRNEY 8.

United States Patent CHANGE KEY LOCK Ernest Norbert Kennedy, London, England Application March 31, 1955, Serial No. 498,373

Claims priority, application Great Britain April 5, 1954 Claims. (Cl. 70-383) This invention relates to change key locks the mechanism of which can be altered at will to work with any one of a number of different keys.

Hitherto such locks have had elaborate and costly mechanism requiring complicated adjusting operations. In some cases a special key was necessary the wards of which were capable of being adjusted to take up various positions.

One object of the present invention is to provide a change key lock of inexpensive construction having simple means for altering the mechanism to enable the lock to be operated by any one selected key out of a number of different keys. A further object is to provide a lock in which the alteration is effected by the selected key itself, so that thereafter, until subsequent alteration is made, the lock can be operated only by this key or by one identical to it.

A change key lock according to the present invention comprises a fixed part and a movable part which carries sliding tumblers adapted to be lifted by the correct key from a position in which they prevent movement of the movable part to a position in which they permit such movement, and the effective length of at least one tumbler is adjustable so that the lock can be altered to operate with keys of different patterns.

By the term lifted as applied to the tumblers is meant the movement which is imparted to the tumblers by the insertion of the correct key, whetherthis' movement is against. the actionof gravity or some other force.

1 By the effective length of a tumbler is meant the distance between a point on the tumbler that touches the key and an end of the tumbler that lies flush with a contact surface between the movable part and the fixed part whenthe correct key is in the lock.

The invention is applicable to locks of the rotatable cylinder type in which the cylinder constitutes the movable part and the barrel the fixed part, and also to looks of the type in which the movable part can slide in the fixed part.

Each adjustable tumbler may comprise a shank which constitutes, or cooperates with, a locking member which locks the, movable part by extending across a contact surface between the movable part and the fixed part and occupying grooves or holes in both these parts when the lock is in the locked condition, and a lifting member which is engaged by the key and which is in frictional engagement with the shank so as to be slidable thereon to alter the effective length of the tumbler butfonly by the application thereto of a force substantially in excess of that normally required to lift or lower the tumbler.

One form of the invention is suitable for use with constant depth keys, that is to say keys in which the profile of one edge is the reverse of the profile of the opposite edge. In a lock suitable for use with such keys, the lifting members may be engaged by both edges of the key such that insertion of a key when the shanks are held against sliding movement in the movable. part adjusts the position of the lifting members on the shanks in comformity with the profile of this key.

Preferably the adjustment of the effective length of the adjustable tumbler or tumblers is effected automatically by inserting a new key when the movable member is in a position away from the locked position. Certain forms of the lock include means for adjusting the tumblers to their maximum effective length, and means for reducing their effective length, where necessary, to suit the profile of an inserted key. This is the case more particularly Where the key is of the type having its operating profile along only one edge.

The means for adjusting the tumblers to their maximum effective length may comprise a member (termed herein for convenience the neutralising member) insertable from outside the lock, when the key is removed, to engage the lifting members and force them in the lowering direction (i.e. the direction opposite to the lifting direction) while the shanks are restrained against movement in the lowering direction. After insertion and withdrawal of the neutralising member, all the lifting members are set to the maximum effective tumbler length. member in the lifting direction. If the shanks were also restrained against movement in this direction, the lifting members would then be adjusted into a position corresponding to the highest point on the key profile which has passed beneath them, and might therefore not correspond to the actual height of the part of the key profile that corresponds to this lifting member. In order to overcome this difficulty, the shanks are permitted to move in the lifting direction with the lifting members, so that their ends will project beyond the contact surface, and the fixed part of the lock includes means for forcing the shanks back flush with the contact surface as the movable part is moved by the key towards its locked position. Thus the effective length of each tumbler is adjusted to conform to the corresponding part of the key profile.

In another form of lock suitable for use with keys having their operating profile on only one edge, the adjustment of the effective length of the adjustable tumbler or tumblers may be effected automatically solely by inserting a new key when the movable member is in a position :away from the locked position and then moving the movable member, with the key in place, out of the position in which the new key was inserted. In one such lock the means for setting the lifting members to the maximum effective tumbler length comprises a ramp formation on the key and corresponding surfaces Inserting a key will now move each lifting.

3,; shanks 'back flush 'with' the contact surfaces after a key has been inserted and the moving part is being moved towards its locked position so that the effective length of each tumbler is adjusted to conform to the corresponding part of the key profile.

In the case of a lock of the cylinder type, the means for forcing the shanks back flush with the cylinder surface may comprise a cam surface'in the barrel, leading from the outer limit of the recessinto which the shanks are lifted by'the insertion of the; key to the normal barrel diameterat or near 'a position opposite the groove orholes in -the"'b'ar r'el whichthe shanks engage when the Y lockis in the locked condition;-

In one-form of lock embodying the invention there" is aspecial position of the-movable member for the insertion of a new keyto adjust the lock; into 'whi'ch'special position the movable member can be movedfrom the locked position or from the [unlocked position only by the key to which the lockis already adjusted.

'In order to prevent withdrawal or'irlsertion of akey except in those positions of'the movable member in which such withdrawalorinsertion are permissibleg there" may be a guard m embcr' which engages anotch in an inserted key and which partially obstnuctsthekeyhole to prevent withdrawal or insertion of the key at all pogtions of the movable member except those in which such-withdrawal or insertion are permissible, the-keyhole lying clear of the guard member in'these'positions-so that keys can then be-fr'eely inserted and withdrawn;- In the case of a lock for which aneutraliser member is necessary,

the guard member may also serve to obstruct 'access to the aperture throughwhich 'the neutralise'r member is inserted, except when'th'e movable member' is-in-a posi- 4 cylinder 1t) mounted" for"rotation"in" a barrekll which is fixed in the door or other part that is to be locked. The cylinder is prevented from being withdrawn rearwardly, i.e. towards the right in Figures land 4, by a flange 12 around its left-hand end which fits into a corresponding recess in the barrel. Withdrwal of the cylinder forwards, i.e. towards the left in Figures 1 and 4, is prevented by a cross-piece 13 which is screwed to the rear end of the cylinder and which also provides the connection for a tail piece 14 which passes through the thickness of the door and engages the knob which is provided on the latch portion-of-the lock which is fitted on the inside of the door. The cylinder is built up from several discs 17 Which are-clamped together by screws the tubular part 22 ofea'ch lining-member iss'ucir that its position in relation to the shank can only be altered by the application of a force substantially-greater than that which is normally required to-lift and lower" the tumblers,

tion appropriatefor'the insertion of theneutralising" member.

The lock may be so disposed that the tumblers fall into their lockedposition by gravity, with-or without the assistance of'springs Alternatively, spring force alone may be relied on;

The invention may-be performed" in various-ways and two different forms of lock embodyingthe invention will now besp'ecificallydescribed-by way of example" with reference tothe accompanyin'g'drawings,in whieh'r Figure 1 is' a side View of one ofthe locks for use with a key having only one operative edge;

Figure'Z-is a fr'on t view ofthe lock shown in-Fig ure lj Figure 3 is a rear view'of the lock' shown inFigure 1; Figure 4 is a longitudinalsection throughthe barrel of the lock'of Figure 1 in the locked condition, with part of the cylinder in section;

Figure 5' is a cross-section taken on the line-V-V of Figure -4;

Figures -'6 to 10 are cross-sections taken on the line X''Xin Figure 4 showirigthe lock invariolls conditions; Figure 11 is a side view 'of the neu-tralisingmember for the-lock of Figure 1; a

Figure 12 is a section of the neutralising member taken on the" line XII -XII in Figure 11;

Figure 13 is a front view of the other lock; which' is" for use with aconstant depth key;

Figure 14'is a longitiidinal section' of the lockshown in Figure 13;

FigureslS to 17 are cross sectionstaken on"the"'liiie XV-XV in Figure 14;

Figures- 18' and 19 are horizontal section's taken on the line xvn'rxvnr' inFig'ure 17; with"two'different keys in' place;

Figure'ZO is a perspective' View of a'tur'tiblenof the The lock shown'in'the Figuresd to'lO is' of the"rota't able cylinder type, that is to say it comprises a rotatable Running longitudinally through the cylinder is a keyway 25' and-a hole-26 for a neutralis'ing 'member 27-" (Figures 11 and 12).

Formed" in'the bottoni of the barrel 11 is -a lineof holes 28 whileformedin the top 'of the barrel" is a 'longitu'dinal: groove 29 Formed'in one side of -the barref there is-arecess 30 which-hash cann su'rfa'c'e '31.-

Mounted' in front-of the-lock and fastened t'o th'e'barrel ll'there' is a guard plate 32 which-has init 'an apert'tire- I 33 providedwith a-qu diant-snaped edge I 34 'term'inating' 'in' two'- notches-35" and 36. The' low-er notch -35 registers" 1 helock is in the with the bottom of the key-way 25 who a locked conditionwhile the u per n'otch "36" reg'isters with the botto'nr offthe" key-way: 25' when the lock is--'ini'- the'- unlocked condition; is aslot'37 which when the look isiri -theuiilockedcon dition registers with the hole 26 for the neutralising member} which 1 is v blanked off 'at all othentimesi The key'38is provided' with anotch in it s-'-lower edge-Wit when the key isins'erted is' 'in line with the quadrant '-34? The quadrant 34' enters :thi notch in the' ke'y wheneverthe keyis in a positiori 'int'ermediate bet-Ween' 'the' l'ockedand 3 unloeked-positiens'to' reventwithdrawal of 'thekeyi Ii1 these extreme posturing-however, the: loweredge of tlie key registers with 'thenotch 35"or witli the notch 36- of the" guard-plate" so' 'that the keycan "be withdrawn and re insertedi The lock works as follows:

When the lock is in-the locked cohditiorithecylindr is in 1 the position in whichiris-shown in Figures; "4; Sand 6*in which the lifting members lie atthe bottoms of-"the' recesses-"19 so that the lowerends' of theshanks 20 project into the holes 28 I at" the bottom of 'the barrel r and:

prevent the cylinder from rotating in thebarre'li I-f-"now" corresponding" to -the actual positions of adjhstmenteff Also"*formed in theggu'ard plate 32 correct key in place, however, the shanks 20 are clear of theholes 28 and ofthe groove 29 so that the cylinder can be rotated to unlock the lock as shown in Figure 7. If now it is desired to adjust the lock to suit a different key, the lock is held in the unlocked position of Figure 'l by. holding the knob 15, and the original key 38 is withdrawn. The neutralising member 27 is then inserted into the hole 26. As the neutralising member is inserted it presses on the small wing portions 23 of the lifting members and forces. the lifting members to the right hand end of the shanks as shown in Figure 8. The shanks 20 cannot move during this operation since their right hand ends are pressing to the right against the interior surface of the barrel. The new key 38 is then inserted, as shown in Figure 9. This moves all the tumblers to the left. They can move freely in this direction because the left-hand ends of the shanks 20 are free to enter the recess 30.. The distance. by which a tumbler is moved to the left corresponds to the highest point of the profile of the key 38 that has touched the larger wing 24 of its lifting member during the insertion of the key. The knob is then released andthe cylinder is turned back into the 'locked position. During this movement the projecting ends of the shanks will come into contact with the cam surface 31 which will progressively force the shanks back intothe cylinden. However, the lifting members 21 can only move until they come up against theicorresponding part of the profile of the key, so that the shanks will be forced jalong through the tubular parts 22. Finally, when the lock. has been returned to the condition shown in Figure 10 the relative adjustment of the lifting members and the shanks is complete. The key 38 can now be withdrawn, and the lower ends of the shanks will fall once more into the holes 28. The lock can now only be unlocked by the new key 38 The provision of the'guard plate 32 withits quadrant 34 prevents the key '38?- from being withdrawn until the cylinder has been fully returned to the position shown in Figu'relt), thereby ensuring that'the lifting members 21 will all take up their correct positions of the adjustment on the shanks 20." The cylinder need not be built up fromdiscs 17, but could be made in one piece, for instance as .a die casting. In almodification of the lock shown in Figures 1 to 10, the lock can be left in the unlocked condition without risk of its being adjusted to suit a new key by someone not in possession of the original key, sinceit must be turned by the original key into a special position before the adjustment can be carried out. In this modification, depicted in dotted lines in Figures 2 and 5, additional grooves and/or rows of holes 29a and 30a are provided opposite both ends of the shanks 20 and into which the shanks 20 can enter when the lock is inthe unlocked condition and the original key is withdrawn. Thus, in this modification the angle between the locked and unlocked positions of the cylinder is rather more than 90. In order to adjust the lock, the cylinder is turned by the original key until the shanks 20 are opposite the deep end of the recess 30. The original key is then withdrawn, the neutralizer is applied, the new key is inserted, and the cylinder is turned into the locked position. An additional notch 36a is provided in the quadrant of the guard plate 32 for the unlocked position, the notch 36 being at the said special position, to permit the withdrawal of the original key.

In a further modification shown in Figures 21 and 22 thelock is constructed so that it can be used with a key.

from the lock when the movable part is away from the locked position (i.e. when the bottoms of the shanks 60 are held flush with the contact surface) the ramp formation comes into contact successively with the bottom edges of the said apertures 56 in the lifting members 57 and forces all the lifting members down to their lowest positions on the shanks. Insertion of a new key will lift the tumblers without altering the positions of the lifting members in relation to the shanks because, as the ramp formation 59 is near the tip of the key, it will already have passed each lifting member before this lifting memberis reached by the leading part 61 of the operating profile of the key. Thus the ramp formation cannot hinder the lifting of the tumblers. Final adjustment of the lifting members on the shanks to suit the new key profile is effected by turning the key back to the locked position as described in connection with the lock shown in Figures 1 to 10.

If the tumblers are to be lifted against gravity both in the locked and unlocked positions, the lock may be so positioned that in the locked position the shanks of the tumblers lie at approximately 45 to one side of the vertical central plane of the lock, and in the unlocked position they lie at approximately 45 to the other side of this plane, so that the tumblers will fall into their lowest positions on removal of the key in either the locked or unlocked positions. i

Another form of lock embodying the invention is shown in Figures 14 to 20 This form of lock is suitable for use with constant depth keys (-i..e. keys-of which the top and-bottom edges have complementary profiles) and no neutralising member is required. This lock is also of the rotatable cylinder type, and comprises a cylinder, 40 which can rotate in a barrel 41. Withdrawal of the cylinder from the'barrel is prevented by the provision of a flange 42' on the front of the cylinder and by a set screw 43 which engages in a circumferential groove 44 in the cylinder. Extending longitudinally through the barrel are a lower groove 45- and an upper groove 46. Extending transversely through the cylinder are three slots 47 in which are accommodate tumblers 48. i Each tumbler (see Figure 20) comprises a shank 49 which contains a rectangular slot 50, and on the shank is mounted a lifting member 51. Each lifting member is made of spring steel with its edges bent over to grip the sides of the shank witha firm frictional grip. In each lifting member there is a rectangular slot 52 which is shorter than the rectangular slot 50. in the shank and which is of substantially the same length as the depth of the' constant depth keys 53 and 53 which canbe i tions of adjustment corresponding to the profiles of the new key. The shanks 49 are prevented from movingused in the lock. A key-way 54 passes'throu-gh the centre of the cylinder 40. Attached to the rear end of the cylinder is a formation 55 by which the cylinder is connected to the latch.

This lock works as follows: 7 l

When the lock is in the locked conditionas shown in Figures 14 and 15 the tumblers drop into their'lowe'st positionsin which the lower ends of the shanks all project into the lower groove 45 of the barrel. In order to unlock the lock the correct key 53is: inserted which,

as shown in Figure 16, lifts all the lifting members to,

a height sufficient to bring their associated shanks wholly within the cylinder. The key can then be turnedinto the position shown in Figure 17 to unlock the lock. If the key 53 is withdrawn when the lock is held in the unlocked position and a new key 53 is inserted, as shown in Figure I 19, this will have the effect of moving the lifting members along their shanks into new posi-- during this operation because their ends lie against side walls of the barrel away from the grooves 45 and 46. The lock has now been re-adjusted to suit the new 7 key 53 and after it has been moved into the locked position. only the newkey 53 will beable to unlock it. Inthe examples described :the tumblers fall bygravity into the. locked 'positionso the lock must be mounted. in such .a .Way that when it:is in the locked condition the tumblers are.vertical. If it is desired so to position:the lock that ,the locking movement of the tumblers is other than vertically downwards, then it willbe necessary to provide springs which act on the tumblers to ensurethat they return to the locked position onwithdrawal of the key.

in orderto'ensurethat the relative positions of the lifting members and shanks are not altered inadvertently, the construction may be such that only thelifting member comesin contactwithany partof the lock or key during the operation 'oflocking or unlocking, the shank being protected from contact with any member or part of the lock, other than lifting member, except during the operation of resetting with a new key or endeavouring to unlock the lock after the insertion of a wrong key.

Whatl claim as-my invention and desire to secure by Letters Patent is;

' 1; A-change key lock comprising a fixed part, a movable part with a key-way formed therein mounted in said fixed part, a plurality of slidable tumblers of adjustable effective length carried bysaid movable part and adapted to be lifted, by a key -,of a profile corresponding to the actual effective lengths of said tumblers inserted into said keyway, from a position in which they prevent movement of said movablepart to'a position in which they permit such movement, each of said tumblers comprising a shank and azliftin'g member which is adapted to be engaged by any keyinserted into said keyway and which is infrictional engagement withsaid shank so as to be slidable thereon to alter'the effective length of the tumblersbut. only bythe application thereto ofaforce substantiallyinexcess of that normally required to move said tumblers, means operative to engage said lifting members to force said lifting members along said shanks in the direction to increase the elfective length of said tumblers while said shanks are held against movement inthe same direction by engagement of said shanks with said Qfixed part, and means operative toengage said tum.-

blers during relative movement between ,any'key inserted into said keyway and said fixedpart to produce relative movement betweensaid lifting members and said shanks in the. opposite direction to decrease the eflfective length of said tumblers toan extent determined by the profile of the inserted'key engaging said'lifting members.

2. A change key lock as claimed in claim 1, for use with 'keys having parallel upper and lower profiles, in which the lifting members have portions engaged by both profiles of thekeys such that'insertion of any such key when the shanks are held against sliding movement in the movable part adjusts the position of the lifting members on the shanksin conformity with the profiles of this key.

3. A change key lock according to claim lin which said means operative to engage-said lifting members to increase the effective length of said tumblers consist of means operative to force said lifting members of all the tumblers along said shanks into a position in which all said tumblers have their maximum effective length.

.4. .A-change keylock as claimed in claim '3 in which said means for adjusting said tumblers to their'maximum effective length comprises -a-neutralising member insertble-from outside the lock, when there is no key in said keyway, to engagethe lifting members and force them in the lowering direction while the shanks are restrained against mQvement in this direction, and ,in which said means operative to decrease the effective length of said tumblerscornprisesa portionof the fixed part of said lock having. a contact surface contacting said movable part and shaped to force the shanks back flush with said contact surface after any key. hasbeeninserted and the movable. part is being moved towards its locked position, so that the effective length of each tumbler is adjusted to conform to the corresponding part of the profile of said inserted key.

, 5. A change-key lock as claimed in claim 4 in which there is a guard member whichengages a notch in an inserted. key and which partially obstructs-the keyway to prevent withdrawal and insertion of the key at all positions of said. movable member except those in which such withdrawal and insertion are permissible, said keyway lyingv clear of said guard, memberin these positionsso that-keys can then be freely inserted and withdrawn, and

a in which said guard member also prevents insertion of said neutralizing member except when said movable member is in a position appropriate for the insertion of said neutralizingv member.

6. Achange key lock as claimed inclaimB in which said meansfor adjusting, saidv tumblers to their. maximum effective tumbler length comprises a rampformation on a key presented in said keyway and corresponding surfaces on the lifting members which are engaged by the said ramp formation. as saidkey is withdrawn .fromthe lock when the movable part is away from the locked position and the shanks are .restrained from movement in the lowering direction of the. lifting members whereby all the lifting members are forced along the shanks to the maximum extent in the lowering direction, and in which the fixed part of the lock .has a contact surface contacting said movable part and includes said means adapted to decrease the effectivelength of said tumblers, said last-mentionedmeans being means for forcing .the shanks back flush with said contactsurfaceafter any key has been inserted and the movable partis'being moved back towards its locked position so that the effective length of each tumbler is adjusted toconform to the corresponding part of the profile of said inserted key.

7. ,A change key lock as claimed in claim 3 which is of the rotatable cylinder type .in which said movable part consists of a cylinder and said 'fixed part consists of a barrel having a cylinder bore in which said cylinder is rotatably mounted, and said means operative to decrease the effective length of said tumblers comprises .a cam surface in said barrel leading from the outerlimit of a recess into which, the shanks .are,v lifted by theinsertion of any key, to said cylinder bore opposite...at..least one other recess in thebarrel which the shanks enter when the lock is in the locked condition.

.8. A change key lock as claimed in claim 1. in which there is, a special positionof themovable. member .for the insertion of a new key to adjust the lock, into which special position the movable member can bemoved from the locked position or from the unlocked position-only by the key to which the lock is already adjusted.

9. Achangekeylock'as.claimedin claim 1 in which, in order to prevent withdrawal or insertion of a key except in selected positions of the movable member, there is a,guard member which engages a notch in an inserted key and which partially obstructs the keyway to prevent withdrawal or insertion of the key at all positions of the movable member except those in which such withdrawal, .or insertion are permissible, the keyway lying clear of a the guard member in .said selected positions so that keys can then be freely inserted andwithdrawn.

10. A change .keylock .comprising a .fixed part; a: relatively movable part, a keyway formed in one of :said parts, a plurality .Of SlldflblfittllIIiblCIS ofjadjustable effective length carried by .said one part andiadapted; to be lifted, by a key of a profile corresponding to the actual elfective lengths of said tumblers inserted into said keyway, from a. position .inwhich they prevent movement.

9 frictional engagement with said shank so as to be slidable thereon to alter the effective length of the tumbler but only by the application thereto of a force substantially in excess of that normally required to move said tumbler, means adapted to force said lifting members along said shanks in the direction to increase the effective length of said tumblers carried by said one part while said shanks are held against movement in the same direction by engagement of said shanks with said other part, and means operative by relative movement of said two parts adapted to produce relative movement between said lifting members and said shanks in the opposite direction to decrease the efiective length of said tumblers to an extent determined by the profile of the inserted key engaging said lifting members.

References Cited in the file of this patent UNITED STATES PATENTS 1,610,224 Dalbone et al. Dec. 7, 1926 1,850,323 Heyer Mar. 22, 1932 2,194,469 Fremon Mar. 26, 1940 2,232,017 Wilder Feb. 18, 1941 2,232,137 Rolph Feb. 18, 1941 2,647,391 Uher Aug. 4, 1953 

